The impact of the casting thickness on the interfacial heat transfer and solidification of the casting during permanent mold casting of an A356 alloy

Many important quality indicators for components manufactured using permanent mould casting, such as the presence of shrinkage porosity, microstructure features, dimensional stability, cycle time and filling mechanisms are controlled directly or indirectly by the heat transfer mechanisms linking the casting to the mould. While interfacial heat transfer in permanent mould casting has been significantly investigated and widely reported in the literature, the geometrical dependence of heat transfer parameters has not been studied or reported in detail. Understanding this dependency is very important as the same cast component most often is constituted by different sections and geometrical variations. In this paper, experimental methods and analytical correlations have been developed and presented that enable an accurate determination of the time dependent interfacial heat flux density and heat transfer coefficient at the casting-mould interface. The variation of these parameters is investigated and analysed for three different casting sections and two types of thermal barrier coatings.